Hi there, great question!
Remember, a galvanic cell generates a current, and can thus be used to power other processes. In contrast, an electrolytic cell requires a power source to proceed at all (since it is nonspontaneous).
So a simple question you can ask yourself when confronted with an electrochemical cell is, "Is a separate power source provided?" If so, you're likely powering a nonspontaneous reaction, so you're dealing with an electrolytic cell. If not, you're probably looking at a galvanic cell.
The passage also gives several more hints as to the galvanic nature of this cell:
In the first sentence, it mentions that biostarch batteries "convert the energy stored in starch bonds into electrical energy." This implies that our battery is producing an electrical current on its own. Similarly, the caption for Figure 1 references "generating electricity." Later in the passage, we see that starch batteries "generate sufficient power for commercial use." At this point, we know for certain that our battery is galvanic, since an electrolytic cell would not generate power - it would require external power to do anything at all.
Good luck with your studies!
